Differential amplifiers having a large common mode voltage range have been known and circuits are known wherein one power supply terminal voltage is embraced in the common mode range. For example in many applications one power supply terminal constitutes system ground. In this case it is often desirable to operate a differential amplifier input circuit at ground so that the input operates about the potential of the grounded power supply terminal. The prior art circuits adapted for such operation work well with the input at ground but will not function when the input is operated at a level near to the potential at the other power supply terminal.